Microscopic polyangiitis with diffuse peribronchovascular nodular involvement: Case report

Abstract

Microscopic polyangiitis (MPA) is a systemic necrotizing vasculitis that affects small vessels with no immune deposits. MPA is a rare disease. The incidence of MPA is approximately 1:100.000 per year. The etiology of this disease is unknown. Pulmonary involvement is mainly characterized with ground-glass attenuation, consolidation, thickening of bronchovascular bundles, and honeycombing on computerized tomography (CT). We report a patient with an atypical pattern of pulmonary involvement which is diffuse peribronchovascular nodular infiltration. A 59-year-old male patient presented with symptoms of shortness of breath, cough, purulent sputum, back pain and hemoptysis. Laboratory studies depicted increased serum creatinine levels, hematuria and proteinuria. His chest X-ray and CT of thorax showed bilateral diffuse peribronchovascular nodular infiltrations. Circulating myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (p-ANCA) was positive. Renal biopsy was obtained because of hematuria, proteinuria and increased creatinine level and revealed crescentic glomerulonephritis associated with small vesel vasculitis which was consistent with MPA. He was treated with corticosteroid and cyclophosphamide. At the end of two months of treatment, renal function and other pulmonary symptoms improved.